(a) Technical Field
The present invention relates to a thermoplastic elastomer composition. More particularly, the present invention relates to a thermoplastic elastomer composition for use in manufacturing a joint connecting a glass run and an inner-belt.
(b) Background Art
Weather strips are generally used to seal the space between the body of a vehicle and the door frames thereof to block infiltration of external impurities, reduce wind noise at high speed, prevent the doors from shaking, and for a variety of other purposes. Typical weather strip types include body/door weather strips that are installed between the door body and the vehicle, glass runs that seal peripheral edges of door glass moving up and down, inner-belts, and outer-belts.
Weather strips are formed of elastic and durable materials in order to maintain excellent sealing performance. Weather strips are generally formed of an ethylene-propylene-diene monomer (EPDM) synthetic rubber, an ethylene-propylene monomer (EPM) synthetic rubber, or a thermoplastic elastomer. In particular, highly elastic EPDM is widely used in the conventional art in order to improve sealing performance of weather strips. Recently, the use of thermoplastic rubber weather strips has been increasing due to improved elasticity of thermoplastic rubbers and advancing designs/shapes of weather strips.
In general, a glass run and an inner-belt are separately manufactured and then assembled during a door assembly process. In this regard, a narrow chink or gap is formed between the two parts at their respective contact surfaces, which may increase wind noise at high speed, thereby increasing the level of noise in the interior of the vehicle. This assembly process has several disadvantages. For example, the assembly process typically requires the use of environmentally hazardous chemicals such as adhesives or primers to connect the glass run and the inner-belt. Another disadvantage is that the presence of manufacturing defects in the components to be assembled such as, for example, the presence of burs in the glass run, result in components that must be discarded because they cannot produce a satisfactory joint, which increases substantially the cost of vehicle production.
Accordingly, there is a need in the art for thermoplastic elastomer compositions that overcome the above-described disadvantages of the conventional art.